3 added 14 characters in body

I'm using following circuit for a boost converter using MC34063A IC.

The circuit is designed for 24v24 V, 250mA250 mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In case of no load I get the very high output of 43v43 V which doesn't change even if I change the value of potentiometer  (R45). This is, I think, the no load behavior of a boost converter, we need a minimum load, so this makes sense. So if I put a load of 1kOhm1 kohm, the output drops to 25-29 volts, over the complete range of potentiometer(R45). Now if use a load of ~150 Ohmsohms (160mA160 mA at 24v24 V), the output drops to ~16.8v8 V and doesn't change by changing the value of R45. What could be the issue here  ?

Similarly, I use following circuit for a buck converter, designed for a 3.3v3 V, 100mA100 mA output. With 7v7 V input the converter works fine, but with 5v5 V input the voltage drops to 2.9v9 V, and doesn't go to 3.3v3 V at any value of potentiometer.

Edit 1: Following is the layout for Boostboost converter. I had to remove the rest of the pcb's components and tracks to make it more readable.

I'm using following circuit for a boost converter using MC34063A IC.

The circuit is designed for 24v, 250mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In case of no load I get the very high output of 43v which doesn't change even if I change the value of potentiometer(R45). This is, I think, the no load behavior of a boost converter, we need a minimum load, so this makes sense. So if I put a load of 1kOhm, the output drops to 25-29 volts, over the complete range of potentiometer(R45). Now if use a load of ~150 Ohms(160mA at 24v), the output drops to ~16.8v and doesn't change by changing the value of R45. What could be the issue here  ?

Similarly, I use following circuit for a buck converter, designed for a 3.3v, 100mA output. With 7v input the converter works fine, but with 5v input the voltage drops to 2.9v, and doesn't go to 3.3v at any value of potentiometer.

Edit 1: Following is the layout for Boost converter. I had to remove the rest of the pcb's components and tracks to make it more readable.

I'm using following circuit for a boost converter using MC34063A IC.

The circuit is designed for 24 V, 250 mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In case of no load I get the very high output of 43 V which doesn't change even if I change the value of potentiometer  (R45). This is, I think, the no load behavior of a boost converter, we need a minimum load, so this makes sense. So if I put a load of 1 kohm, the output drops to 25-29 volts, over the complete range of potentiometer(R45). Now if use a load of ~150 ohms (160 mA at 24 V), the output drops to ~16.8 V and doesn't change by changing the value of R45. What could be the issue here?

Similarly, I use following circuit for a buck converter, designed for a 3.3 V, 100 mA output. With 7 V input the converter works fine, but with 5 V input the voltage drops to 2.9 V, and doesn't go to 3.3 V at any value of potentiometer.

Edit 1: Following is the layout for boost converter. I had to remove the rest of the pcb's components and tracks to make it more readable.

I'm using following circuit for a boost converter using MC34063A IC.

The circuit is designed for 24v, 250mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In case of no load I get the very high output of 43v which doesn't change even if I change the value of potentiometer(R45). This is, I think, the no load behavior of a boost converter, we need a minimum load, so this makes sense. So if I put a load of 1kOhm, the output drops to 25-29 volts, over the complete range of potentiometer(R45). Now if use a load of ~150 Ohms(160mA at 24v), the output drops to ~16.8v and doesn't change by changing the value of R45. What could be the issue here ?

Similarly, I use following circuit for a buck converter, designed for a 3.3v, 100mA output. With 7v input the converter works fine, but with 5v input the voltage drops to 2.9v, and doesn't go to 3.3v at any value of potentiometer.

Edit 1: Following is the layout for Boost converter. I had to remove the rest of the pcb's components and tracks to make it more readable.

I'm using following circuit for a boost converter using MC34063A IC.

The circuit is designed for 24v, 250mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In case of no load I get the very high output of 43v which doesn't change even if I change the value of potentiometer(R45). This is, I think, the no load behavior of a boost converter, we need a minimum load, so this makes sense. So if I put a load of 1kOhm, the output drops to 25-29 volts, over the complete range of potentiometer(R45). Now if use a load of ~150 Ohms(160mA at 24v), the output drops to ~16.8v and doesn't change by changing the value of R45. What could be the issue here ?

Similarly, I use following circuit for a buck converter, designed for a 3.3v, 100mA output. With 7v input the converter works fine, but with 5v input the voltage drops to 2.9v, and doesn't go to 3.3v at any value of potentiometer.

I'm using following circuit for a boost converter using MC34063A IC.

The circuit is designed for 24v, 250mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In case of no load I get the very high output of 43v which doesn't change even if I change the value of potentiometer(R45). This is, I think, the no load behavior of a boost converter, we need a minimum load, so this makes sense. So if I put a load of 1kOhm, the output drops to 25-29 volts, over the complete range of potentiometer(R45). Now if use a load of ~150 Ohms(160mA at 24v), the output drops to ~16.8v and doesn't change by changing the value of R45. What could be the issue here ?

Similarly, I use following circuit for a buck converter, designed for a 3.3v, 100mA output. With 7v input the converter works fine, but with 5v input the voltage drops to 2.9v, and doesn't go to 3.3v at any value of potentiometer.

Edit 1: Following is the layout for Boost converter. I had to remove the rest of the pcb's components and tracks to make it more readable.

1

# MC34063A Poor load regulation in case of boost and buck converters

I'm using following circuit for a boost converter using MC34063A IC.

The circuit is designed for 24v, 250mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In case of no load I get the very high output of 43v which doesn't change even if I change the value of potentiometer(R45). This is, I think, the no load behavior of a boost converter, we need a minimum load, so this makes sense. So if I put a load of 1kOhm, the output drops to 25-29 volts, over the complete range of potentiometer(R45). Now if use a load of ~150 Ohms(160mA at 24v), the output drops to ~16.8v and doesn't change by changing the value of R45. What could be the issue here ?

Similarly, I use following circuit for a buck converter, designed for a 3.3v, 100mA output. With 7v input the converter works fine, but with 5v input the voltage drops to 2.9v, and doesn't go to 3.3v at any value of potentiometer.